Response:

We would not expect to observe large changes directly. Evolution
consists mainly of the accumulation of small changes over large periods
of time. If we saw something like a fish turning into a frog in just a
couple generations, we would have good evidence against evolution.

The evidence for evolution does not depend, even a little, on observing
macroevolution directly. There is a very great deal of other evidence
(Theobald 2004; see also evolution proof).

As biologists use the term, macroevolution means evolution at or above
the species level. Speciation has been
observed and documented.

Microevolution has been observed and is taken for granted even by
creationists. And because there is no known
barrier to large
change and because we can expect small
changes to accumulate
into large changes, microevolution implies macroevolution.
Small changes to developmental genes or their regulation can cause
relatively large changes in the adult organism (Shapiro et al. 2004).